1. Field of the Invention
The present disclosure relates to a photovoltaic inverter including a switching device to be connected to a photovoltaic module, and more particularly, to a photovoltaic inverter properly connected to a photovoltaic module through a switching device regardless of connection polarities.
2. Background of the Invention
In general, a photovoltaic inverter (or a grid-connected inverter) is a power conversion device that connects an input electric power system and a commercial electric power system and transmits electric power from the input electric power system to the commercial electric power system.
An input terminal of a photovoltaic inverter is connected to an input terminal of a photovoltaic module (or a solar cell module) and an input terminal, and here, since the photovoltaic module has two polarities, i.e., positive (+) and negative (−) polarities, the input terminal of the photovoltaic inverter also has two positive (+) and negative (−) polarities.
An alternating current (AC) is nonpolar, eliminating the attention to be paid for polarities in case of connection, but a direct current (DC) has positive (+) and negative (−) polarities, so a positive (+) polarity should be connected to a positive (+) polarity and a negative (−) polarity should be connected to a negative (−) polarity.
In this context, regarding the photovoltaic inverter, if an operator does not connect properly positive (+) polarities and negative (−) polarities between a photovoltaic module and the photovoltaic inverter in installing the photovoltaic inverter in the photovoltaic module, namely, if the photovoltaic inverter and the photovoltaic module are connected at mutually different polarities, when the photovoltaic inverter is operated, a large current flows instantaneously, causing a spark to damage the photovoltaic inverter.